<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/149986>149986</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clang::Expr::IgnoreParenImpCasts() Clang ICE since version 20 with c++20
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          mariete1223
      </td>
    </tr>
</table>

<pre>
    ## Assertion

No assertion given

## Stack dump

```
Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/clang++ -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -x c++ -std=c++20 <source>
1.      <source>:9:54: current parser token ';'
 #0 0x0000000003fc4898 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3fc4898)
 #1 0x0000000003fc1cc4 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3fc1cc4)
 #2 0x0000000003f06498 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x0000736e53842520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x000000000785c1d4 clang::Expr::IgnoreParenImpCasts() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x785c1d4)
 #5 0x000000000696ac3b calculateConstraintSatisfaction(clang::Sema&, clang::Expr const*, clang::NamedDecl const*, clang::SourceLocation, clang::MultiLevelTemplateArgumentList const&, clang::ConstraintSatisfaction&) SemaConcept.cpp:0:0
 #6 0x000000000696d659 CheckConstraintSatisfaction(clang::Sema&, clang::NamedDecl const*, llvm::ArrayRef<clang::AssociatedConstraint>, llvm::SmallVectorImpl<clang::Expr*>&, clang::MultiLevelTemplateArgumentList const&, clang::SourceRange, clang::ConstraintSatisfaction&) SemaConcept.cpp:0:0
 #7 0x000000000696dc85 clang::Sema::CheckConstraintSatisfaction(clang::NamedDecl const*, llvm::ArrayRef<clang::AssociatedConstraint>, llvm::SmallVectorImpl<clang::Expr*>&, clang::MultiLevelTemplateArgumentList const&, clang::SourceRange, clang::ConstraintSatisfaction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x696dc85)
 #8 0x0000000007047ee7 clang::Sema::CheckConceptTemplateId(clang::CXXScopeSpec const&, clang::SourceLocation, clang::DeclarationNameInfo const&, clang::NamedDecl*, clang::ConceptDecl*, clang::TemplateArgumentListInfo const*) (.constprop.0) SemaTemplate.cpp:0:0
 #9 0x0000000007049f7d clang::Sema::BuildTemplateIdExpr(clang::CXXScopeSpec const&, clang::SourceLocation, clang::LookupResult&, bool, clang::TemplateArgumentListInfo const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x7049f7d)
#10 0x0000000006ba3c37 clang::Sema::ActOnIdExpression(clang::Scope*, clang::CXXScopeSpec&, clang::SourceLocation, clang::UnqualifiedId&, bool, bool, clang::CorrectionCandidateCallback*, bool, clang::Token*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6ba3c37)
#11 0x0000000006706bf6 clang::Parser::tryParseCXXIdExpression(clang::CXXScopeSpec&, bool, clang::Token&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6706bf6)
#12 0x0000000006706e9a clang::Parser::ParseCXXIdExpression(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6706e9a)
#13 0x00000000066eaf0a clang::Parser::ParseCastExpression(clang::CastParseKind, bool, bool&, clang::TypoCorrectionTypeBehavior, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66eaf0a)
#14 0x00000000066ea6ce clang::Parser::ParseCastExpression(clang::CastParseKind, bool, bool&, clang::TypoCorrectionTypeBehavior, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66ea6ce)
#15 0x00000000066ec5f7 clang::Parser::ParseCastExpression(clang::CastParseKind, bool, clang::TypoCorrectionTypeBehavior, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66ec5f7)
#16 0x00000000066ed796 clang::Parser::ParseRHSOfBinaryExpression(clang::ActionResult<clang::Expr*, true>, clang::prec::Level) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66ed796)
#17 0x00000000066f76fb clang::Parser::ParseConstraintExpression() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66f76fb)
#18 0x000000000679869c clang::Parser::ParseConceptDefinition(clang::Parser::ParsedTemplateInfo const&, clang::SourceLocation&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x679869c)
#19 0x000000000679f982 clang::Parser::ParseTemplateDeclarationOrSpecialization(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifier) (.part.0) ParseTemplate.cpp:0:0
#20 0x000000000679fcea clang::Parser::ParseDeclarationStartingWithTemplate(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x679fcea)
#21 0x00000000066bc820 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66bc820)
#22 0x000000000667942c clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x667942c)
#23 0x000000000667a315 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x667a315)
#24 0x000000000666c07a clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x666c07a)
#25 0x0000000004972ad8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4972ad8)
#26 0x0000000004c64eb5 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c64eb5)
#27 0x0000000004be1c7e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4be1c7e)
#28 0x0000000004d58991 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4d58991)
#29 0x0000000000d9f10f cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xd9f10f)
#30 0x0000000000d95d6a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#31 0x00000000049d94a9 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#32 0x0000000003f06934 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3f06934)
#33 0x00000000049d9abf clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#34 0x000000000499c6bd clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x499c6bd)
#35 0x000000000499d74e clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x499d74e)
#36 0x00000000049a57b5 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x49a57b5)
#37 0x0000000000d9b5bf clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xd9b5bf)
#38 0x0000000000c4fa44 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc4fa44)
#39 0x0000736e53829d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#40 0x0000736e53829e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#41 0x0000000000d95815 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xd95815)
```

## Program

```
template <typename T> concept PerfectSquare = [](){}
([](auto) { return true; }) < PerfectSquare <class T>;
```

To quickly reproduce:

https://godbolt.org/z/955M65Pq6

</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzkWluTmzgW_jXqFxVdWNwf_IDp9Exnk0lXu3c3by4hhK1tLBFJdOz59VsSuDH4kkvZqanK1CTB6HK-853D0QcSVootOaVTEMxAcHeDG70ScrrGklFNJwh5N7kotlOAPIA8mCpFpWaCAzcFbvqXgHh3By7ZK-3ud73nGpMXWDTrursdut3_bvooxVLiNcRy2awp1wp4KQToXtQaoHsi1jWrqHTopq6EpNLcqzBfOm_2lKNlw18Aus8Z3zUDNANoBp1l8RXL0vGhs4SOMPPiujazN7pu9K2CzrqqXtfQcTZx6GC1dtSWa7wB3h3jmlbQKblwXqnMhaKmHTpz6DhLQhwtREVWmHHg3Z3Fazorjmu1Eho6JRGVkE7B8JILpRlRrQ0isVoNb28g2fmhdAG8u-4nciHwMiUaSSjw3gE3ndwCNxnc89IEeGngGzZJIyXlGtZYKiqhFi-UQ4Ai4M3M367h23Ohu3F3_3kl8eMkhoYb4KXAS9VWtRePknFtA_osMaEAxX0nib8uhNKS4jVAIUAZZFwDlECA4guFFKCZu-ngAZR04Ccj8BNC_GPgs4pi3tSf-JwtOa4Aihtu876AlTAmrgHVgOmhoiFUN_STGGYm-E-UiFcqty22PzEvKmMx7jgc9MkE13Sjb0ldAy917Z92fq-bP_JCGnixjwKTLtapiuUA3W_icBH6TsV4s3GWvGkbyK0St6GFbIf0gP19wFEckEnhw9ZNy-m7TS3bq4clF5I-Ykn5w7rOsNLKGr44qR2KHmOwjzFMQky8HBJckabCmmaCKy2xyVusmSoxsZULxXtezOkadzk78g0SMxygdNT2F17T4o6S6lSHuX0YPwiCW3ODxo9NpdkH-kqrZ7quDcq0K4AfmNK7Kcd4TnkSGpKNC5nghNbH8iIcUVSEQQKzFSUvP0_PcQr65y6VEm-faAm8bG9UqpQgDGta9JZNyRoMna9xVf2HEi3kw7quhjPYlEOpHTTG9HPEtrF6wnxJL0d5NKacxAEck9oa-d44_PaMX7iSdFHpK0k8qHauH1EanY-ZCf7O8YdiGK7s8-c5ETWd15ScJ-JEmTChxtK2mNA_8FKcmuctNQ4rUYfyeOOxoO3bSTvab-3vWor61t3l_m7skeRPRkQmZVQcJ3LWsKroGWxT7aIsfhDipamfqGqq3dBciOonibjoStYS0-afETIDGRbm2CPeifxLif7EW7qoUocV2zB2JBX2uPxBFv_NvzS4YiWjhcnzAY1H6MyElNQ-uhnmBSvMQoyrKsfkpYN1LAZGm16H6o7MnuqBaAwjN8zLcB_Lo5XL7bWWW_sz-_z5NOVHuD3t4lWqWetE7yIau0gTfMrFE_61HlwFKk1wD9UbQA0pLt1vQMVKn4wEVtp2-hfjxWGejtP-eVuLPl2ftzWd0RV-ZUIejr1Karbu9mT4YzJCQn8nMkLzYrkjIxiRQYIyujwZ_ywGjI89A-GIgSJKTlYqe_305_xTOWMcy-0pIlLrXLcmHtV6KINaNrQTinsdaklJt7Aa1XcdBoyPPQNDKR2WUVjm53PgTUQOCLgKVoumxxoPi24Shwn5FtZWnpWMs0PNf9C_F0tn5OB4Kb_OemOd611PRq6XSYzOur7zZE_nfpJm_WS4Yn_jQzJ2HYXsPoF82-3sAEGRai1Z3miqDnukhFClLIaSGVZa9VtjqVvhOwA-Ur4Aecgdk0Do-ZVsz_m5xlIzvvwv06udiV9AwDUyw7j9lhloKLbCnMTI_V5SfnUGfLvH2MZ1VgFLUk_hUMyFUeKj83Xl3UZTyXF1kspLUGF6ML40Nlrdex0urLc9FyO1GGEjE84WGlHbxap9B94n4VONvzT0UcvhKmg6_iGFeW0sj3726N_EPoqiqejDuhZSz7V9Yq_yTLVu9iSMVGJI3Oiw0KTz55Of8oZS5gqALaQe8EDJ-UmEcBEPXxkL-gflrTTZiRFKGk3T3bewK8DsgPQwB3LLJ6FP80Fy3UtTeHhxBOeVELYYeoQDOeTndEIiOiSytfnAlcac0ONcnnbpKvnb4ey9GAglvwjiJJkMv75bvL0zr28FNz7n7FVKUIevRz_QOm6RlBO3hIRMFmtsJoiPf5Rd4b0NhU5ZD-6hDL4KVlzHiRblmw_DTT-3SIIixHBHezZ5tnUhPvuN-MChcPhZ2czRLdR7UjWBhWSvVB7Kp-Fenp8UiY8TS8nepGXDbaIupGXVtraPXrv3CbyUdN-aFiUfFvbWcJc62SQT6zXmxfgpPho9uwtr7onaWMeGgD1ytGR82S0XbWjfBiwWZLOZTNofOVaMLJTt3lE46GxuLMzLi1a75tF0uKrMoyDkXrvpko5eTFvC7RCAogqv8wIDFPVUoXi37_le5EeCcbBbmXj7G6vH9iTblqeGz3FJq-2Ay_Nxu8buq0XcJ7w3Ti6cl_B3To7Ru83xLPCHrCUkzIuTrNmo4YOVcUfloHSPBpoOp95nz3RNB3Jmz7HLqgTrdp9KIzGTFJFPf5SU9yJXpxl5L_KDHbRztfgtA2rMTPDtwYHvJ7FLk19CpSGrp3IouBIcREPBtQ_7bu96IBCOKINTIfiFVF5BrVp6evKi0RqeB7uStlMiO_C2lKQHe8anVuiLaw-DrMc9UH8u8Uvs-9AgvrThdurecDI8IYOSIvnBEzJ2yNuEvjuekPouXCzMmIXSWOrFnlvfbYL6eyYmY6EWTwLYTn75OJnJO9N7B_X643zdkb3Ds3y6-2IFgZfpbU05XlP4DLx3Jq8IrTV8pLKkRM-_NFiabnewPW_YiYBoBqI7ayh-u48bLWw6RjMoqW4k7z5Lz6DpbFq87GBio_iUssaBNzt05VnALw0jL9UWSlpLUTTtW5JtXGld2xNj6B6g-6UoclHpWyGXAN3_DdB9EgQfw-DxSwjc9KaYekXiJfiGTidR4E2iaDIJblZT34-CoJjgsJiEeUDyvCyLOCq9MqdhgTz_hk2RiwI3QshNvNgLbnMSxRGlcRTFeZLTGPguXWNW3Zpn1Zi_YUo1dDrxkyQObyqc00rZA5sIdVFEILi7kVMzwMmbpQK-WzGlVT-FZrqi0_Hnfnt1-vxWZrrDh-wdVIwTCl-pVExwiFz4lekVfDuYeNPIajqij-lVk98SsTZJbqpO-49TS_E_SkzWWrcUQPedZ69T9P8AAAD__3OTKYA">